Final answer:
Julia wears a very wide belt, which aligns with her affluent and idealized image. This belt is noted to be visible at the back of her figure, suggesting it as the correct item worn around her waist.
Step-by-step explanation:
From the descriptions provided, it is apparent that Julia wears something around her waist that signifies her status. The text mentions a very wide belt that Julia wears, which complements the rest of her idealized and affluent attire. This belt, Steven notes, may be seen at the back of Julia's figure with a little cleft that has been carved in horizontally, indicating the presence of the tied belt hanging down.
Additionally, her dress is complemented by a sacred knot, which could be misconstrued as something worn around the waist, but in actuality, it is part of the dress tied at the nape of the neck, trailing down the back. Thus, the correct answer to the question would be (a) A leather belt, based on the historical context given in the text describing her attire.